Means for casing cutting



Dec. 26, 1950 l A, STANTQN 2,535,964

MEANS FOR CASING CUTTING Filed July 30. 1945 l A f 4AusT|N N sTANToNINVENTOR.

Patented Dec. 26, 1950 Manus ron oAsiNo CUTTING 'Austin N. Stanton,Garland, Tex., assigner of fifty per cent to .lohn .l. lleet, SanAntonio, Tex.

Application July 3l), 1945, Seria-l No. 607,716

(Cl. 166-l) `-9 Claims. 1

This invention relates to apparatus for cutting, perforating andwindowing well casing and it has particular reference to such apparatusfor `performing the functions set forth While the casing is suspended ina Well.

A mixture of equal molecular parts of `iron oxide and aluminum reactsexothermically to produce aluminum oxide and `pure iron, producing agreat deal of heat in the process. This is a well-known process and themixture is marketed under the trade-name of Thermit It has a Agreat manyuses, `chiefly in welding. Other similar mixtures which produce largeamounts of heat at high temperatures =and which `contain withinthemselves all the elements necessary to complete the chemical reactioncome within the rmeaning of this invention.

The present invention seeks, among its objects, to adapt thismaterialfor similar materials, to the cutting, perforating or windowingof oil well `casing Ordrill stems while the latter are suspended in thewell. Present methods of cutting oasing involve the loweringof a millmachine into the hole on the end of the drill stem, engaging the cutterswith the casing and rotating Athe -mill `until the casing iscut oiT. Notonly is considerable `labor and time involved in lowering themill butoccasional mechanical diiculties are encountered, such as a broken-drill stem, leaving junk in the hole, often with complete loss of thef.

hole. Perforating is commonly done by means of guns which necessarilyproduce small and easily clogged. holes in the casing and surroundingformations. While the gun may be lowered on a cable, it is of hard steeland if `lost in the hole, f

may resultin complete loss of the latter. Windowing is ordinarily doneby knives lowered on drill stern and is subject to the same difficultiesas themill mentioned above.

It is therefore the prime object of the invencular annular perforationsor even several wnr dou/s in one operation.

Another object of the invention is vtoprovide constructed of soft orfriable materials which be armed up and washed mit of the hole if losttherein.

2 With the foregoing objects as paramount, the invention has furtherreference to certain Ifeatures of accomplishment which will becomeapparent as the description proceeds, takenin connection with theaccompanying drawings where- Figure l is a view in vertical sectiontaken on line i--l of Figure 2 showing one form of the invention, inwhich the uppersection has an 'annular recess containing heat generatingmaterials.

`Figure 2 is a view in transverse section, taken on line 2-2 on Figure1.

Figure 3 is a slightly modied form of the `invention in which aplurality of sections are threaded together, each having Thermitcontaining recesses therein` Figure 4 is still another form of theinvention, showing a plurality of vertically and circumferentiallyspaced Thermit recesses in a single, elongated plug.

Figure 5 is a fragmentary view in vertical section of a plug in whichthe rIlhermit recesses assume a different form, 'over which the fusiblecover is secured by bolts.

Figure 6 is a fragmentary view in vertical section in which the plug hasan elongated Thermit recess, employed in windowing casing.

Figure 'l is a View in transverse section, taken on line l--l on Figure6, and

Figure 8 is a view taken on line 8-8 on Figure 4.

Continuing with amore detailed description of the drawing, reference lisprimarily made to Figure l wherein l denotes a section of well casing inwhich the casing cutting, perforating or windowing apparatus of the`invention -is suspended.

The device of the invention consists primarily of a sectional plug, theupper section Il of Which is composed preferably of asbestos or plastic,immune or at least partly so tc intense heat. The lower end i2 of thesection H of the plug is reduced slightly in diameter and is externallythreaded to be received by the correspondingly threaded lower sectionI3, formed preferably of refractory or ceramic material. The section itispreferably bullet-shaped for `ease inloweringthe plug into pipe orcasing, which is accomplished by means of a Wire line or cable attachedto a bail it affixed to the upper plug section it. The refractory plugsection I3 is made hollow to contain a material of considerable Weight,such as lead I5.

Referring again tothe upper section ll `of the plug, it is apparent thatthe member is provided with an annular recess or groove i6 about itsmidsection whose concave base is in communication at at least two pointswith an axial opening I 'I in the section H, by means of lateralopenings I8, to which further reference will be made presently. l

The annular recess IE is filled with a quantity of Thermit I9, which iscovered by a band or ring 20, of fusible material, suitably held in anannular recess about the plug section l I, which recess is slightlygreater in width than the Thermit groove I6.

The plug, composed of the sections Il and i3 is of a diameter slightlyless than the inner diameter of the casing l@ into which it is loweredso that there will be but little clearance between the walls of theseelements.

To ignite the Thermit, when the plug is properly positioned in a casing,an electrical current conductor or cable 2l is disposed in thelongitudinal opening il' of the upper plug section, which has separatecircuits 22 and 22a, passing through the opening I3 to respectiveheating elements 23 and 23a, embedded in the Thermit I9 of recesses l5.By completing the circuits through conductors 22 and 22a', heatsuiiicient to ignite the Thermit I9 is generated in the elements 23 and23a, respectively, causing the Thermit, in predetermined quantity andlocation, to react violently, producing suflicient heat to fuse themetal of the casing immediately adjacent to the Thermit.

, In the structure shown in Figures l and 2, the

casing I!! will'be entirely severed at the point of operations. In theoperation, the band 2i) will, of course, be quickly disintegrated.

The other forms and applications of the principle hereinbeforeexplained, and as shown in the remaining figures of the drawing differonly to the extent that instead of completely cutting the casing, thelatter is windowed or perforated. For this reason, the same charactersof reference used in preceding views are employed to indicate like partsin these variations.

In Figure 3 is shown a plug composed of internally and externallythreaded sections H whose recesses I 6, containing Thermit i9, mayconsist of annular cavities or cells and, by virtue of the superimposedrelationship of the sections Il, perforations may he made in the pipe invertically spaced relationship. The size or diameter of theperfor-ations will, of course, be determined by the quantity of Thermitused or, in other words, the size and capacity of the cavities iiicontaining the Thermit. In this connection, it is further pointed outthat the particular shape of the cavity, i. e., the concaved form of itsbase is calculated to focus the heat of combustion towards the centralpoint of operations, from which fusion will spread to the maximum range,producing a cut of a width not much greater than that of the Thermitcavity.

In the construction shown in Figure 3, a suitable weighted lower sectionshown fragmentarily in this figure, is provided.

The construction shown in Figure 4 is not unlike that illustrated inFigure 3 except that instead of a multiplicity of superimposed andinterchangeable sections, the plug consists of a single mandrel l l inwhich the Thermit recesses or cavities l are provided in a similarmanner.

In Figure 5, the plug l l is provided with Thermit recesses or cavitiesit whose bases, instead of being concaved, are substantially fiat, as

shown and the Thermit charges I9 are enclosed by bands 20, held in placeby bolts or screws 24.

Figures 6 and 7 illustrate a form of plug in which the mandrel Il isprovided with an elongated recess or cavity i6, containing Thermit I9,which latter, upon ignition will produce an elongated window in thecasing in which it is suspended. Other features of this form of theinvention are identical to others previously shown and described.

Figure 8 shows an alternate cross section of Figures 3, 4 or 6, showingcircumferentially divided cavities, either of circular section, as inFigures 3 and 4, or elongated section, as in Figure 6. These would, ifignited simultaneously, provide several circumferentially spacedcircular openings or elongated openings in the casing. However, byigniting the charges separately and moving the plug in the hole anypredetermined pattern of holes may be obtained.

The operation of the described apparatus would simply be to lower theplug to the desired depth in the casing, ignite the Thermit and withdrawthe plug. The molten steel from the melted casing would form in smalldrops and fall to the bottom of the hole or simply remain mixed withadjacent mud.

Manifestly, the apparatus as shown and described is capable of somemodification and such modification as may be construed tofall within thescope and meaning of the appended claims is also considered to be withinthe spirit and intent of the invention.

What is claimed is:

l. A well pipe cutting apparatus including a solid body of heatresisting material adapted to be lowered into a well pipe and having anouter surface provided with recesses of predetermined depth and sizecircumferentially spaced about said outer surface, an axial passageextending through said body, a plurality of lateral passagescommunicating between said axial passage and said recesses, and amixture of equal molecular parts of iron oxide and aluminum contained insaid recesses for presentation to an area of said well pipe to beremoved, identical to the area of said recesses, electrical currentconducting means in said passages, and means embedded in said mixtureenergizable by current produced in said latter means for generating heatto effect ignition and consequent fusion of said mixture to meltadjacent areas of said well pipe by physical proximity and contact ofsaid fused mixture.

2. In a well pipe cutting, perforating and windowing apparatus, a plugcomposed of a solid body of high heat resisting material adapted to besuspended in a well pipe, said plug having an outer surface providedwith vertically and circumferentially spaced recesses, a plurality ofmeans extending longitudinally and laterally through said body to saidrecesses for conveying electrical current thereto from the surface, amixture of equal molecular parts of iron oxide and aluminum in each ofsaid recesses, a heating element embedded in said mixture and energizedby current in said latter means to melt said mixture and cause the sameto settle by gravity and expand longitudinally to contact adjacent areasof said pipe.

3. Well pipe cutting apparatus comprising an elongated solid plug ofheat resisting composition adapted to be lowered into a well pipe andhaving circumferentially spaced cells in its longitudinal outer surface,said body being provided with an axial passage extending through saidbody and a plurality of lateral passages communicating with said axialpassage and said cells, a mixture of nonexplosive heat generatingsubstance in said cells, an electrically energizable means embedded inthe mixture in each oeil and means in said passages for conveyingelectrical current to said energizable means to ignite and fuse saidmixture and cause the same to flow by gravity against adjacent areas ofsaid pipe to melt the same.

4. In means for cutting out portions of tubular structures by heat; aheat resistant body adapted to be disposed in desired position within atubular structure, said heat resistant body having an outer surfaceprovided with a plurality of spaced shallow recesses, said recessesbeing adjacent to the portions of the tubular structure which are to becut out when said heat resistant body is disposed in desired positionwithin said tubular structure; a body of nonexplosive exothermic mixturein each of said recesses; and means for initiating the chemical reactionof said bodies of exothermic mixture whereby the heat generated by saidreaction of said bodies of exo-thermic mixn ture will melt out portionsof said tubular structure adjacent said recesses.

5. In means for cutting out portions of tubuiar structures by heat; abody of refractory material adapted to be positioned in desiredpositions within a tubular structure, said body having an outer surfaceprovided with a plurality of vertically spaced annular grooves; a bodyof exothermic mixture in each of said grooves; and means for selectivelyinitiating the chemical reaction of said bodies of exothermic mixturewhereby the heat generated by ne reaction will melt out portions of saidtubular structure adjacent said grooves.

6. In means for cutting out portions of tubular structures by heat; abody of refractory material adapted to be positioned in desiredpositions within a tubular structure, said body having an outer surfaceprovided with a plurality oi vertically spaced annular grooves, a bodyof exothermic mixture in each of said grooves; a means formed of heatdestructible material associated with each groove for retaining saidbody of exothermic mixture within said grooves; and means forselectively initiating the chemical reaction of said bodies ofexothermic mixture whereby the heat generated by said reaction will meltsaid body of nonexplosive exothermic mixture .in each of said recesses,said bodies of exothermic mixture being positioned adjacent the portionsof the tubular structure which are to be cut out; means formed of heatdestructible material associated with each of said recesses forretaining said body of exothermic mixture in said recess; and means forinitiating the chemical reaction of said bodies of exothermic materialwhereby the heat generated by the reaction will destroy said heatdestructible means and melt out portions of said tubular structureadjacent said recesses.

8. In means for severing tubular structures by heat; a body ofrefractory material adapted to be positioned in desired position withina tubular structure, said body having an outer surface provided with anannular groove; a body of exothermic mixture in said groove, said bodyof exothermic mixture being adapted to `be positioned adjacent thetubular structure at the point at which the tubular structure is to besevered; and means for initiating the chemical reaction of saidexothermic mixture whereby the heat generated by said reaction will meltsaid tubular structure adjacent said groove.

9. In means for cutting out portions of tubular structures by heat: abody of refractory material arranged about a longitudinal axis andadapted to be positioned in desired position within a tubular structure,said body having an outer surface provided with an elongated recessextending parallel to said longitudinal axis; a body of nonexplosiveexothermic material in said recess, said body of exothermic materialbeing adjacent to the portion of the tubular structure which is to becut out when said body of refractory material is disposed in desiredposition within said tubular structure; and means for initiating thechemical reaction of said body of exothermic material whereby the heatgenerated by said reaction of said bodies of exothermic material willmelt out an elongated portion of said structure adjacent said recess.

AUSTIN N. STANTON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,582,184 Mims Apr. 27, 19261,641,483 Greene Sept. 6, 192'? 2,144,208 Van Meter Jan. 17, 19392,201,290 Greene May v21, 1940 2,302,567 ONeill Nov. '17, 1942 2,315,496Boynton Apr. 6, 1943 2,436,036 Sefenbaugh Feb. '17, 1948

